In the wake of superstorm Sandy’s massive destruction to coastlines in the East Coast, many experts suggest that a sea wall barrier could have minimized the deadly storm surge that swept away homes and knocked out power to millions.

The catastrophe prompted New York Gov. Andrew Cuomo to propose this week that a feasibility study to consider the idea.

Oceanography professor Malcolm Bowman told ABC News that a sea wall barrier could have stopped Sandy’s 14-foot storm surge earlier this week that crippled the city by flooding the subway system and parts of the electrical grid.

“If we had implemented these barriers by now there would have been no damage to New York City resulting from Sandy. By that I mean no damage coming from the ocean,” Bowman said, who teaches at Stony Brook University on Long Island.

Places like St. Petersburg, Russia, London and the Netherlands could serve as models since their sea walls control flooding for areas that are either at sea level or below.

Invited by Bowman and his colleague Douglas Hill, two European engineering firms have drawn up proposals for walling most of New York off from the sea. The barriers are very high tech and in one design, a wall lays flat on the bottom of the harbor, pivoting up when needed to block a storm surge.
Although the sea barriers offer great protection for low-lying coastal areas, they come with a hefty price tag. One proposal for New York’s harbor costs more than $6 billion. Skeptics say the massive barriers would not work on long stretches of the coastline like the New Jersey shore.

To be sure, some scientists have reservations about the storm-surge barrier concept.

Some are concerned about how the structures could affect tidal flow and other environmental features of New York Harbor — and about whether barriers would be socially fair.

"Who gets included to be behind the gate, and who doesn't get included? ... How do you make that decision in a fair way?" Robert Swanson, an oceanographer who is Bowman's colleague at Stony Brook, said in an August interview.

Other experts question whether barriers would even work in the long term. Klaus H. Jacob, a Columbia University climate-risk researcher who has advised New York City officials, has noted that given the unknowns of climate change, any system designed now could prove inadequate in the future.

But advocates believe that America's largest city needs to take bigger steps given its concentration of people and financial infrastructure.
"With the kind of protection that has been considered so far, you cannot protect a multimillion-inhabitant city that runs part of the world economy," said Piet Dircke, who has worked on the extensive system of sea barriers in the Netherlands with the Dutch engineering firm Arcadis.

His firm's proposal is to build a barrier in the Verrazano Narrows between Brooklyn and Staten Island, shielding Upper New York Bay. It would be supplemented by two smaller barriers, one between Staten Island and New Jersey and the other on the East River. Such a barrier would have protected Manhattan and much of Brooklyn and Staten Island from Sandy but left southern Brooklyn and John F. Kennedy International Airport exposed.

Robert Trentlyon, a New York community activist who has been advocating for storm-surge barriers, sees the one-two punch of Hurricane Irene in 2011 — which came close to flooding subway stations in southern Manhattan — and Sandy as a sign that the time has come.
"Having had two storm surges within one year, and their both being major ones, I just find it very difficult to think the city could not go ahead and act," the retired local newspaper publisher said by phone Sunday from his Manhattan apartment, which was left without power. His neighbourhood, though not his building, was among those that flooded.

In August, U.S. Rep. Jerry Nadler urged city officials to take a comprehensive look at storm-surge barriers, bulkheads and other flood-fighting devices.

New York isn't the only city in the world (or country) that is exposed to storm surge damage. And, unlike many other cities, New York appears to have a relative easy way to protect itself.

The attached slides, from a 2009 deck, offer one potential solution to New York's storm-surge exposure — a porous barrier across the entrance to New York Harbor. According to the deck, such a barrier would cost $7 billion.

To put that $7 billion in perspective, its significantly less than the $12 billion price tag on one of our new aircraft carriers, the U.S.S. Gerald Ford.

So, whaddya say, folks? Time to consider a storm surge barrier for the country's biggest city? Or should we increase defense spending and build two-thirds of another aircraft carrier?

As you are pointing out, the majority of the casualties in NYC were in Staten Island and other areas that wouldn't have been protected by these barriers anyway, and they could have made the water out of the barriers to rise more.
In the other hand, the floods in Manhattan flooded the subway and that affected the entire city. The flooding of some office buildings in Lower Manhattan also means a huge economic loss in terms of economic output, even if the buildings itselfs are not severely damaged but the companies they hold are force to be out of bussines for several days.
But the worst damage was in areas that wouldn't have been protected by these barriers anyway.

There was a debate about that in the NYT

These are two, among other four, articles that make a debate about whether they should build a storm barrier.

The original proposal to build three barriers and protect New York Harbor inside the Verrazano Narrows does not protect the 300,000 people in Brooklyn and Queens who live around Jamaica Bay within the floodplain of a Category 2-3 hurricane (below 16 feet above sea level). Worse yet, experiments with our storm surge model show that these barriers would slightly worsen the flood elevations in Jamaica Bay. So, this plan may be perceived as choosing “winners and losers,” and the area with the greater population (and votes) is in the latter group.

Another barrier proposal would protect nearly the entire city, but features massive levees over Rockaway Peninsula and other low-lying nearby land areas. Who really believes that New Yorkers will be interested in taking the “New Orleans approach” to stopping storm surges?

Also, every barrier plan that has been presented would reduce exchanges of our city’s estuarine waters with the ocean, degrading water quality and changing temperature and salinity. This would have complex effects on our rebounding ecosystems and coastal fisheries, a source of pride for a growing number of New Yorkers.

The silver lining is that now we’ll finally have the political will to tackle all the sensible, efficient defense measures we've been neglecting. A great deal of protection can come from simply making better small-scale and (this time) watertight adaptations to protect subways and electrical infrastructure, such as retractable subway stairwell domes or rubber subway air vent covers. Let’s leverage the amazing designers and engineers of New York City and have open design competitions. This could be a 1-year or 2-year process, and we could dramatically improve our resilience in the rare event that seawater comes into our city.

I would add that a barrier at the Verrazano also will leave unprotected much of Staten Island, which had most of the casualties related with the floodings.

There is no easy -- or inexpensive -- way to fully prevent the enormous damage that Hurricane Sandy inflicted on New York City. Because of the city’s location, at the confluence of the Atlantic Ocean, Long Island Sound and Hudson River, the nation's largest metropolitan economy is highly susceptible to coastal storms and tidal flooding. However, the Organization for Economic Co-operation and Development recently found that the metro area's lack of protective measures is an outlier when compared to better prepared peer cities like London, Tokyo and Shanghai.

Yet proposals for "hard" infrastructure investments -- like storm surge barriers -- are not new, and numerous types, styles and functions have been suggested. As a nation of innovators, I have no doubt we can engineer a solution. The new flood defense system in New Orleans passed its first tests after the devastation from Katrina in 2005. So why isn't it getting done in New York?

The cost of such a system is generally considered the most significant hindrance. To be sure, at $6 billion or so to build and about $75 million each year to operate, the costs are large. But perhaps not prohibitive compared to other projects like $15 billion for the World Trade Center reconstruction, $8 billion for the Long Island Rail Road link to the East Side of Manhattan, and even the $2.5 billion for new stadiums for the Yankees and Mets. The costs of Hurricane Sandy's devastation (more than 30 people killed, $20 billion in damage, millions in lost economic activity each day) also provide important perspective.

Including three barriers, it would cost certainly much more than $ 6 billion.

...but this seems only to protect from a "surge". What happens when sea levels truly begin to rise? We are thinking about the same things in San Francisco. BTW, we should have, at least, done this years ago...
Perhaps I / we should come-up with a 1,400 foot ladder?

__________________Show me a 12 foot fence and I'll show you a 14 foot ladder.

...but this seems only to protect from a "surge". What happens when sea levels truly begin to rise? We are thinking about the same things in San Francisco. BTW, we should have, at least, done this years ago...
Perhaps I / we should come-up with a 1,400 foot ladder?

A long wall should be placed on the other side of the Narrows that would run the length of Long Island and Staten Island so that the entire city and close neighbors would be protected. It would cost a fortune, but the end result would stop storm surges from creating a problem in NYC for a very long time. It would also prevent NYC from going underwater in the future as this barrier would work in a similar way to those that protect the below-sea-level areas of the Netherlands.

This would be one of the largest engineering feats not only in US history but in world history. I can only think of a few cities that have a harbor that is right by the ocean like NYC.

__________________There is only one corner of the universe you can be certain of improving, and that's your own self.
-Aldous Huxley

An aerial view of the hurricane barrier site in Stamford, Conn., in 1986. An expert estimates that any such barrier system to block storm surges in the low-lying areas of New York City would cost at least $10 billion to $17 billion.

By MIREYA NAVARRO
November 7, 2012

Quote:

As the storm chugged toward the Eastern Seaboard at 3 p.m. on Oct. 27, an engineering crew in Stamford, Conn., was at the ready. It was time. With the click of a computer mouse, machinery on the seafloor groaned into action and a gate was slowly pulled from the deep, locking into place high above the surge from Long Island Sound. Two days later, when storm waters from Hurricane Sandy ripped through the East Coast, much of Stamford, a city of 124,000, sat securely behind a 17-foot-high barrier that easily blocked an 11-foot surge. The Army Corps of Engineers estimates that the two-mile-long barrier system, completed in 1969, helped prevent about $25 million in damage to businesses and homes. The protected area encompasses about 600 acres, including downtown Stamford.

The technology of movable sea barriers, from Stamford’s modest flap gate to London’s mighty 10-gate system in the River Thames, has long intrigued engineers and planners contemplating a solution for low-lying areas of New York City. The notion is that such a system could one day block surges from Long Island Sound and the Atlantic Ocean into the East River and New York Harbor. Now, in the aftermath of the devastating storm, one question is front and center: Should New York armor itself with steel and concrete at a cost of billions of dollars? Mayor Michael R. Bloomberg has expressed wariness about the barrier proposal, saying he is not sure the gates would work well enough. Yet, it is clear that his administration’s view is evolving.

The turning point was Tropical Storm Irene, which in August 2011 mostly skirted the city but pummeled other coastal areas in the region. After that storm, the mayor’s Office of Long-Term Planning and Sustainability asked Dr. Aerts, a geographer and an expert on water risk management and climate, to compare the costs and benefits of barriers with those of smaller-scale changes like building levees around sewage treatment plants and elevating subway stations.

Dr. Aerts, who is expected to present a draft of his findings in January, estimates that any barrier system would cost $10 billion to $17 billion. New York would need $10 billion to $12 billion more to shore up the areas on the sides of the barriers, he added. Still, he said, the city should consider building the barriers.

__________________NEW YORK. World's capital.

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